In the field of the production of prostheses for amputated limbs, in particular lower limbs, to which the following discussion will explicitly refer without loss of generality, it is common practice to form a negative cast of the end portion or stump of the amputated limb, then, on the basis of said negative cast, produce a positive model, and form on the latter the attachment or socket portion of the respective prosthesis.
Currently, the negative cast is produced with the limb in a non weight-bearing condition, i.e. at rest. In order to obtain a model as close as possible to the end portion of the limb, the negative cast and/or the model subsequently produced undergo long, laborious and complex custom machining operations.
Once the attachment portion of the prosthesis has been formed based on the model, said attachment portion is customised by fitting it on the end portion of the patient's limb and performing a series of coupling tests in weight-bearing conditions. During these tests, the attachment portion is gradually modelled in order to eliminate localised stress on the limb and/or undesired deformation both of the muscular part and the soft tissues of the limb.
Although universally used, the procedure described not only requires great experience and sensitivity of the prosthetists, but also requires considerable time, entails a high level of patient involvement and essential cooperation of the patient.